Automatic stoker



NOV. 5, 1940. c C LARSEN Re. 21,617 7 AUTOMATIC, STQKEVR Original Filed May 15, 1934 5 Sheets-Sheet 1 Nov. 5, 1940. c. c. LARSEN 7 Re. 21,617

AUTOMATIC STOKER Original Filed ma 15, 1934 s Sheets-Sheet 2 Invenlor Nov. 5,

Original Filed May 15, 1934 C. C. LARSEN AUTOMATIC STOKER 5 Sheets-Sheet 3 Inventor NOV. 5, 1940. m Q R N 21,617

AKJTOMATIC STOKER Original Filed lay 15/1934 Sheets-Sheet .4

Inventor [flzarsen Nov. 5, 1 940.

's. LARSEN R12. 21,617 AUTOMATIC STOKER Original Filed May 15, 1954 5 Sheets-Sheet Invenlor Reissued Nov. *5, 1940 UNITED STATES p Re. 21,517

AUTOMATIC STOKER Clarence G. Larsen, Bismarck. N, Dak assignor to Lignite Combustion Engineering Corporation, incorporation of North Dakota Original No. 2,055,579, dated September 29, 1936, Serial No. 725,810, May 15 1934. Application for reissue September 28, 1938, Serial No. 232,192

2 Claims. (am-115) This invention relatesto stokers for furnaces,

and more particularly to a coal feeding mechanisin therefor.

The principal object of the invention is to provide an automatic stoker that is simple in con struction, dependable in operation and so designed as'to be-swung freely into and out of operative position with respect to the furnace.

The invention, together with its objects and advantages, will be best understood from a study 01 the following description taken in connection with the accompanying drawings, wherein:

Figure 1 is a front elevational view of the stoker.

Figure 2 is a detail view taken approximately on the line 2-4 of Figure 1.

Figure 3 is a top plan view'of the stoker.

Figures 4 and '1 are sectional views taken substantially on the lines 4-4 and 1l, respectively, of Figure 3.

Figures'5 and 6 are detail sectional views taken substantially on the lines 5-! and 83. respectively, of Figure 4, and

Figure 8 is a perspective view of a reciprocating plate forming part of the feed mechanism.

Referring to the drawings by reference numerals, it will be seen that in accordance with the present invention, a portion of the wall 5 of a furnace isprovided with an opening i over which is placed an attaching plate I. The plate I is provided with an inspection door 3 .and a cleanout door 3. Suitable latch means it is provided for the door 3, while latch means II is provided for the doorl.

mentioned plate I, as at i3, and mounted on the plate I! adjacent its free end for alignment with the feed opening ll provided in the plate I is a feed casing I 3 of suitable construction. In the top thereof, the casing I5 is provided with a tunnel-shaped inlet it that aligns with the hopper H for conducting the coal from the hopper Inwardly from the discharge plate "a of the I feed casing it, said casing, at the bottom there- A supporting plate I2 is hinged to the afore- I through an aperture in a cross bar 21 extending of, is provided with a trough-like portion 24 in which operates a rotary beater 25 mounted on a shaft 25. The plate l8, obviously, may be adjusted for exposing the desired portion of the periphery of the beater 25 to control the point of contact of the coal on the periphery of the beater, thereby controlling the velocity imparted to the particles of coal passing over the beater which velocity in turn will control the distance which the particles of coal will be thrown by the beater. In this connection, it will be' noted that the discharge plate i5a of the casing extends into the furnace slightly above the grate line 21. The mechanism for driving the beater 25 will be hereinafter more fully referred to.

Mounted for reciprocation within the casing i5 and across the inletmouth Iii of the casing is a fuel feeding ram 23. The ram 28 is moved along the plate i8, and at the rear end thereof, the ram 23 is provided with it lug or enlargement Zia which has a pin and slot connection. as at 32 with one arm of a lever 33. The lever 33, intermediate its ends, is pivoted between lugs projecting laterally from the casing i5, as at 34.

Supported from one side of the casing it through the medium of a bracket 35 is a gear case 36 clearly shown in Figure 'l. through the, topof the gear case 38 is a stub shaft 31 which, on its upper end, is provided with a disk 33 equipped with a crank pin 40 to which is connected one end of a connecting rod 39. The connecting rod 39 has a threaded end which extends through the apertured free arm of the lever 33. which end of the lever 33 is maintained in operative engagement with the connecting rod 38 through the medium of a fixed collar H on the rod 33 and a hand nut 42 screw-threaded on the free end of the rod 33. By means of this hand Extending nut 42, the amount of lost motion between the collar II and the hand nut 42 may be controlled, this in turn controlling the travel of the ram 28, which again in turn will control the amount of coal moved forward by the ram 23 by each forward movement of said ram.

The aforementioned shaft 26 for the beater 23 also extends through the gear casing 35, and that part of the shaft 33 which extends through the gear casing 33 is connected with the aforementioned shait 31 through the medium of suitable gearing l3.

Mounted on' the plate 1, below the feed casing I5. is a blower which includes a suitable blower casing ll having a discharge :1 extending through a suitable aperture in the plate 1, and

arranged within the casing 44 is the blower fan I so ll mounted on an extension of thesshaft of a motor 46. w

'The motor for driving the fan I! is suitably supported by suspension brackets 41. The brackets 01 are secured at their upper ends to the plate l2, and in this connection it will be understood that the blower casing II is supported from the feed casing. being welded or otherwise secured toone side ofthe casing ll (see Figure 1), so that all of the parts will swing withthe attaching plate I! as a unit. Casing II is welded or otherwisesecuredto plate I! asat w. I

The motor 4. has a belt and pulley drive connection ll with the free end of the beater shaft a and thus it will be apparent that the blower, the beater "and the fuel feedingram 28 are all driven from-the one motor I.

It will be understood that the stoker may be employed with any suitable automatic control equipment, and in operation, when the equiptheopening llinthe meat calls for heat, the motor 40 will be automatically started. The drive from the motor is then transmitted to the beater 2i and the ram 18. with the result that the beater 25 will continuously rotate and the ram- 2| reciprocates. The coal will feedby gravity from the hopper ll through the throat." into the feeding casing I! and by the ram 2| willbe forced forwardly toward the discharge plate lloof the feed casing It. The coal thus forced toward the plate its will pass from the plate It onto the heater 2! to bedlrected by the beater forwardly and through plate 1 into the fire box of the stove.

Attentioniscalledtothefact thatasbest shown in the drawings 1.58.14, the advancing face of the ram fl is stepped to form a bottom adso that it is p perly guldedwithout undue side friction in the feed casing under the action of the swinging lever II. The top of the bottom step forms a ledge to prevent heavy avalanche of fuel directly onto the plate It from the inlet the step and the advancing top step permits the passage of large and f d!!! material into the clogging or obstruction. The fuelpases from inlet ll onto the ledge of anew the feed casing due to the'natural angle of repose of the file] so that the furnace end of the I fuel casing does not become jammed with fuel. The passage formed by the casing It with plate IO, and the ram are both rectangular in transverse crpss section and the fuel is thus fed evenly to all parts of the beater 26. By reason of all these facts the stokerhas great feeding capacity,

the fuel is uniformly ,fed in predetermined amount and the ram'can be properly actuated by expenditure of but little power, but a small quantityof fuel being pushed forward by the bottom step of the ram and the balance of the fuel being carried forwardly by the ram.

Having thus described the invention, what is claimed as new is:

1. A; stoflng device comprisinga supporting plate adapted to be hingedly mounted on a furnace wall, a fuel feed casing mounted on said plate for movementtherewith, said casing being provided with an inlet and an outlet for granular fuel. and having at said outlet a horizontal wall extension merging into an integral inclined plate m rging at its upper end internally of the casing into a substantially cylindrical trough extending transversely of said casing, a rotary heater in said trough for projecting fuel through said outlet, a pair of opposed inclined guide members arranged in said casing and terminating at their lower ends adjacent to, said trough, a bottom plate for said casing slidably engaging with and supported by said guide members, said bottom .plate adapted to be projected across said trough above said beater to control the delivery of fuel to the latter, means for adjusting said bottom plate and securing the latter at the desired adiustment, a fuel feeding ram supp t d by said bottom plate and movable along the bottom plate relative thereto, means for driving said heater,

and means for reciprocating said ram.

2. The combination of a furnace formed with 'afuel opening and an air inlet opening spaced tending forwardly and upwardly from said integral wall'portion, means in said casing forward of said inclined/plate for forcibly feeding fuel from the easing into the furnace, a blower suspended from and supported by the feed casing,

and having an air outlet extending into the furnace through the aforementioned air inlet opening. brackets extending from said supporting plate, a motor supported by said brackets, driving connections between said motor and blower for operating the latter, and other driving connections between said motor and the fuel feeding means for "operating the latter.

CLARENCE c. Leases. 

